Island



(No Model.) 2 SheetseSheet 1.

D; M. THOMPSON. STEAM GENERATOR AND PURNACE.

180.8018188. 'Patented 188188818987R\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\YIT |T s .5 U B l BZ 9 ,B 59

f1' J9. s G J2 l 1 H y/ f /1/ A /V W wrm-5555.' H .m vzw-UH.'

www/.55% 9M ../Zy@

PATENT EEICE.

DAVID M. THOMPSON, OE PROVIDENCE, RHODE ISLAND.

STEAM-G EN ERATOR AND FU RNACE.`

SPECIFICATION forming part of Letters Patent No. 601,488, dated March29, 1898.

Application tiled July 23, 1897.

To @ZZ whom, it may concern.'

Be it known that I, DAVID M. THOMPSON, of Providence, in the county ofProvidence and State of Rhode Island, have invented a new and usefulImprovement in Steam-Generators and Furnaces for the Same; and I herebydeclare that the following is a full, clear, and exact description ofthe same, reference being had to the accompanying drawings, forming partof this specification.

The invention has reference to an improvement in the class ofsteam-generators known in the art as vertical tubular steam-boilers.

In vertical tubular steam-boilers the lower tube-sheet extends over thefire and is subj ected to the direct action ofthe most intense cipitatedscaleforming matter.

heat of the furnace. As the i'mpuri ties in the water are retained inthe steam-boiler when the water is evaporated, the lower tube-sheetforms the natural place of deposit of the pre- Various devices have beenused to prevent the deposit of impurities, the formation of scale, andthe burning of the tube-sheet. The most common of these is the use of anannular space extending below the tube-sheet and inclosing the furnace,so as to form the fire-box for the boiler and a mud-collecting spaceusually below the nre-grate. Such fire-boxes had been provided with thering-doors and were of difficult and costly construction. They limitedthe grate area and by absorbing the heat from the fire prevented themore perfect combustion of the fuel.

The object of this invention is to increase the efficiency of thevertical tubular steamboiler by increasing the grate area of the furnaceand utilizing the fire-box as a flamechamber.

Another object of the invention is to protect the lower part of thefire-box against the corrosion and rotting to which it was exposed inthe former construction.

Another object of the invention is to eliminate the firing-doors fromthe lire-box and to simplify the construction of the lire-box.

A further object of the invention is to secure the more perfectcombustion of the fuel and greater economy.

To these ends the invention consists in the peculiar and novelconstruction of the ver Serial No. 645,712. (No model.)

tical 'tubular steam-boiler and its furnace, as will be more fully setforth hereinafter.

Figure l is a vertical sectional view of my improved steam-generator. Aportion of the barrel of the generator is cut out, so as to show theessential parts more clearly within the required space. Fig. 2 is anexternal side View of the same.

In the drawings, A A indicate the foundation on which thesteam-generator is supported; A', an annular, preferably cast-iron,support for the steam-boiler B. The base of the support A is ofconsiderably greater diameter than the diameter of the cylindrical shellof the steam-boiler. It extends vertically to about the level of thegrate and then curves inward and upwardto form a support for the lowerend of the fire-box of the steamboiler. The lire-doors A2 and theash-pitdoors A3 are pivotally connected and form part of the support A. A4indicates the circular grate, and A5 the central support for the grate.Within the annular support A' is built the wall A6, preferably oflire-brick. This wall curves inward and upward to form an annulardome-shaped furnace, the throat A7 of which extends into the flre-box Band above the bottom of the same. A layer of non-conducting material A8is placed over the support A to prevent the radiation of heat.

The steam-boiler B consists of the cylindrical outer shell B2, the uppertube-sheet B3, the lower tube-sheet B4, the tubes B5, secured at theends in the tube-sheets B8 and B4, the central stays B6, the tray B7,the uptake D, and the annular sheet Biianged at the lower edge, where itis riveted to the outershell B2, the stays'B", and the steam-dome B10.By this construction the steam-boiler rests around its whole peripheryon a support having an extended base of larger diameter than thediameter of the steam-boiler. The lower end of the fire-box of theboiler is above the lire, but this lower end is protected against theaction of the lire by the fire-brick lining of the furnace. The largearea of the grate and the arched lire-brick lining facilitate thecombustion of the fuel and the gaseous products, the contraction of thethroat of the furnace facilitating the mixture of the gases and theirperfect combustion in the name-chamber of IOO the fire-box. The lire-boxis of larger area than the throat of the furnace. The velocity of thegases is diminished to allow time for their combustion before they enterthe tubes, so that little if any unconsumed carbon enters the tubes, andblack smoke is avoided.

The cost of construction of the steam-boiler is much reduced byshortening the fire-box and placingthe doors independent of and belowthe same. The durability of the steamboiler is materially increased,because it is the lower part of the fire-box, when at or below thegrate, that most rapidly deteriorates and is most costly to repair. Thefire-brick 1ining used in the improved boiler sustains the greatest heatand wear and can be renewed at small cost. The efficiency is materiallyincreased by reason of the increased grate area, which in theproportions shown in Fig. l is one-third greater than could be securedin the older construction of the furnace. Economy is secured by the moreperfect combustion of the fuel.

Having thus described my invention, I claim as new and desire to secureby Letters Patentl. In a steam-generator, the combination with avertical tubular steam-generator and a ire-box extending below the lowertubesheet and forming an annular water-leg, of a furnace having a grateof larger diameter than the interior diameter of the fire-box, thefire-brick lining of the furnace lextending into the fire-box, wherebythe lower end of the fire-box is protected against the direct action ofthe tire, as described.

2. In a steam-generator, the combination with a vertical steam-boiler, afire-box eX- tending below the lower tube-sheet to form an annularwater-space and ame-chamber, of an annular support for the boiler havinginwardly-inclined sides the base of which is of greater diameter thanthe cylindrical shell of the boiler and provided with a firing andash-pit door, a furnace the interior diameter of which is greater thanthe interior diameter of the lire-box, a wall of fire-resisting materialinclosing the furnace, said wall curving inward and upward above thelower end of the fire-box, and a circular grate, whereby the products ofcombustion pass through the contracted throat of the furnace into theflame-chamber in the hre-box, as described.

3. In a steam-generator, the combination with'a circular ash-.pit andfurnace, a circular grate, an annular metal casing extending inward andupward to form the support of the steam-boiler, ash-pit and fire doorssupported on the casing, and a fire-brick lining on the inside-of thecasing extending inward and upward above the top of the casing, ofavertical tubular boiler, a fire-boX extending below the lowertube-sheet and below the top of the iire-brick lining of the furnace andforml ing an annular water-space and a flame-chamber, as described 4c.In a steam-generator, in combination, the vertical steam-boiler B havingthe tubes B5, the uptake D and the fire-box B', the circular grate A4 ofgreater diameter than the interior of the fire-box, the fire-brick wallA6 curving inward and upward above the grate, the contracted throat A7of the furnace extending into the tire-box', the lire-door A2 andash-pit door A3, the annular cast-metal support A and the' lagging AS;whereby the fuel is burned in the furnace surrounded by firebrick,discharged into the fire-box of larger area than the throat of thefurnace and conveyed through the annular series of tubes, as described.

In witness whereof I have hereunto set my hand.

D. M. THOMPSON.

Witnesses:

JOSEPH A. MILLER, JOSEPH A. MILLER, Jr.

